It's genuinely possible that the title is all you need; I was tempted to write nothing further. Feel free to take ten seconds and see if it's already clicked. If not, read on.
When something is in your literal blind spot, it's invisible to you, but your brain stitches together everything else around it to make you think that you're seeing a complete picture.
Reality:

Blind spot:

Perception:

We often use "blind spot" as a metaphor to gesture toward things we are unaware of, while also being at least somewhat unaware of our unawareness—we know that something fishy is going on, but we can't quite get our eyes on it.
e.g. "I think I might have a blind spot when it comes to status dynamics."
The thing about status dynamics, though, is that they aren't in one spot. There isn't a whole world that is being fully and accurately perceived, except for one blank space that's being glossed over.
Instead, what's usually going on (at least in my experience) is that the person can see everything, but there's some crucial component of the picture that they are unable to process or comprehend.
What this looks like, in practice, is an inability to distinguish two things which are very, very different, à la red-green color blindness:

"Look," says Alexis. "Look at the beautiful contrast."
Blake hesitates. "...you mean between the trees and the sky?"
Being (metaphorically) color-blind to something can be deeply frustrating. You keep pushing the X button, and very different things keep happening.
e.g. you are learning to play a Formula 1 racing simulator, and it feels like you did exactly the same thing on exactly the same curve both times, but one time you spun out and crashed and the other time you smoothly navigated right through.
e.g. you are repeating back to the native French speaker exactly the sounds she said to you, and sometimes getting nods and smiles and other times getting sympathetic winces.
e.g. you asked your romantic partner what you should have said, instead, to avoid this huge disagreement, and the words they wished you'd said are literally equivalent in meaning, that's the exact same sentiment, what the hell is going on, here?
It's straightforwardly analogous to being literally color-blind, where you might try on one t-shirt, and hear snickers and giggles and see people trying not to laugh, but then you swap it out for a t-shirt that is almost exactly the same shade, you can barely even tell them apart, and suddenly everybody's all encouragement and compliments.
They're the exact same shirt! They're practically indistinguishable!
Yes—to you. But other people make distinctions you do not. Whether because they've got slightly different physical or mental structures, or because they've spent a lot of time focusing on a domain and developed substantial sensitivity to it, or because they came from a subculture where those distinctions were obvious and omnipresent.
(And you make distinctions that are invisible to them, most likely! That seem to them capricious and arbitrary, if not entirely made up!)
Trigger: Notice that someone is being weirdly intense about a meaningless distinction.
Action: Ask "if they were perceiving some facet of reality that I am insensitive to (rather than just making mountains out of molehills), what might it be?"
Trigger: Notice that someone (including you) just used the term "blind spot."
Action: Ask what the thing allegedly "in" the "blind spot" is, and whether it is local, or distributed/omnipresent.
Trigger: Notice that someone is continually ignoring your gestures toward an Extremely Important Thing™, or that they keep failing to successfully extrapolate even though you've laid out a bunch of individual examples and the trend should be obvious by now.
Action: Imagine that they are color-blind to this property, and consider what other proxies or algorithms you might hand them, that are not dependent on directly perceiving the Extremely Important Thing™.
For calibration: mostly-replacing my mental category of "blind spot" with "color-blind" has been one of the ten most useful shifts of my last three years, by virtue of a) giving me a much better starting point for navigating inferential gaps, and b) somehow causing me to be more empathetic? ...I suppose because if the problem is a blind spot, then if they just shift their focus a little, they should see the thing, dammit, whereas if I model them as simply lacking the ability to perceive (even if only because they haven't practiced enough in this domain yet) it suddenly seems much less their-fault if merely shifting their focus doesn't fix it.
YMMV, but at the risk of being too clever by half: there really is a useful distinction, here.
This piece was reasonably well-appreciated (over 100 points) but I nevertheless think of it as one of my most underrated posts, given my sense of how important/crucial the insight is. For me personally, this is one of the largest epiphanies of the past decade, and I think this is easily among the top three most valuable bits of writing I did in 2022. It's the number one essay I go out of my way to promote to the attention of people who already occasionally read my writing, given its usefulness and its relative obscurity.
If I had the chance to write this over again, I might possibly make it longer and more detailed? I'm torn/conflicted. I don't like that short bits of writing tend to be taken less seriously than longer ones; I would prefer a world where the brief essays packed a punch commensurate with their value rather than their weight. But rather than railing against that dynamic, I think I would just ... flesh this out, so as to give it more felt-sense seriousness.
I might, in such a rewrite, also focus more closely on the key point that blind spots don't live in one spot—they tend to be pervasive, and the way in which they tend to be pervasive is an inability to distinguish between lots of different things. If you're red-green colorblind and don't know it, there are thousands of places where it feels like people are drawing completely meaningless and made-up distinctions that literally don't exist; those two objects are literally the same color, what are you talking about? ... and I see this same sort of blindness crop up in e.g. the writings of people who aren't even aware that they're typical minding, or the behavior of people who don't even know that it's possible to not care about monkey status games, or the update procedures of people who can't tell the difference between a logically sound argument and rhetoric/demagoguery.
I think that increasing the general awareness of what a blind spot feels like, on the inside and what a blind spot looks like, from the outside would go a long way toward improving our ability to do collective rationality. It would improve our ability to wisely defer to one another. It would make it much easier to recognize what's actually going on, in situations where one side thinks the other is making mountains out of molehills, and the other thinks the first is callous or disingenuous or motivated by antipathy. It's a pattern whose shape appears all over the place, and recognizing that "blind spot" was a bad handle for it and "color blindness" was a less bad handle for it has been a huge boost for me, both in navigating my own blindnesses and in more quickly recognizing (and having more productive and constructive reactions to) the blindness of others.
Fwiw I don't think it'd make sense to make this post longer. I like the concept/metaphor here a lot, but haven't ended up using it, and I think what'd actually help here is just... periodically seeing "Case Study: Color Blindness Metaphorical Application" posts that kinda space-repetitioned the concept into my brain more.
(Although I guess, for purposes of "if this post ended up periodically highlighted at the top of the frontpage a la the Spotlight feature, it'd be useful for it to be somewhat more complete, and meanwhile that'd still help with the space-r... (read more)